1. Technical Field
Example embodiments may relate to methods for operating controllers. Example embodiments may relate to methods for operating controllers by forming a seed table and/or memory systems including the controller.
2. Description of the Related Art
Pseudo-random numbers are widely used in communication systems or data storage systems. The pseudo-random numbers are used to generate a pseudo-random sequence.
A pseudo-random number is a number that is generated by a predetermined mechanism, e.g., a pseudo-random number generator, using a given initial value.
Since a method of generating random numbers is not regulated, what value or number will be generated cannot be predicted. However, numbers generated by a pseudo-random number generator can be calculated from an initial value of the pseudo-random number generator. Accordingly, to distinguish these numbers from real random numbers, they are called pseudo-random numbers.
A linear feedback shift register (LFSR) is used to generate a pseudo-random sequence. The LFSR can change the pseudo-random sequence by changing an initial value referred to as a seed or changing feedback taps.
As described above, pseudo-random numbers can be calculated using an initial value. Accordingly, a method which does not allow pseudo-random numbers to be easily calculated is required.
A randomizer converts data to randomized data using a pseudo-random sequence generated by the LFSR. A de-randomizer converts randomized data into de-randomized data using the pseudo-random sequence generated by the LFSR. Accordingly, a randomizer or a de-randomizer that does not allow a pseudo-random sequence to be easily calculated is desired.